1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-octanoyloxy-1,3-imidazolidin-2-one herbicide

ABSTRACT

This invention discloses the compound 1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-octanoyloxy-1,3-imidazolidin-2-one and its utility as a herbicide.

This invention relates to a new composition of matter and morespecifically relates to the new chemical compound1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-octanoyloxy-1,3-imidazolidin-2-one. This compound has thefollowing structural formula: ##STR1##

The compound of the present invention is unexpectedly useful as aherbicide.

The preparation of the compound of this invention is shown in thefollowing examples.

EXAMPLE 1 Preparation of 5-t-Butyl-1, 3,4-thiadiazol-2-yl IsocyanateDimer

A saturated solution of phosgene in ethyl acetate (100 ml) was chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5-t-butyl-2-amino-1, 3,4-thiadiazole (10 grams) in ethylacetate (300 ml) was added to the reaction vessel, and the resultingmixture was stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture was then purged withnitrogen gas to remove unreacted phosgene. The purged mixture was thenfiltered to recover the desired product 5-t-butyl-1,3,4-thiadiazol-2-ylisocyanate dimer as a solid having a melting point of 261° to 263° C.

EXAMPLE 2 Preparation of the Dimethyl Acetal of2-[1-Methyl-3-(5-t-butyl-1, 3,4-thiadiazol-2-yl)ureido]acetaldehyde

A mixture of 5-t-butyl-1,3,4-thiadiazol-2-yl isocyanate dimer (6 grams),the dimethyl acetal of 2-methylaminoacetaldehyde (3.9 grams) and benzene(50 ml) was charged into a glass reaction flask equipped with amechanical stirrer and reflux condenser. The reaction mixture was heatedat reflux, with stirring for a period of about 5 minutes. After thistime the reaction mixture was stripped of benzene to yield an oil whichsolidified upon standing. The resulting solid was then recrystallizedfrom pentane to yield the desired product the dimethyl acetal of2-[1-methyl-3-(5-t-butyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehydehaving a melting point of 80° to 82° C.

EXAMPLE 3 Preparation of 1-(5-t-Butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one

The dimethyl acetal of2-[1-methyl-3-(5-t-butyl-1,3,4-thiadiazol-2-yl)ureido]acetaldehyde (16grams), concentrated hydrochloric acid (10 ml) and water (500 ml) werecharged into a glass reaction vessel equipped with a mechanical stirrer,thermometer and reflux condenser. The reaction mixture was heated atreflux for a period of about 15 minutes. The reaction mixture wasfiltered while hot, and the filtrate was then cooled, resulting in theformation of a precipitate. The precipitate was recovered by filtration,dried and was recrystallized from a benzene-hexane mixture to yield thedesired product1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-onehaving a melting point of 133° to 134° C.

EXAMPLE 4 Preparation of 1-(5-t-Butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-octanoyloxy-1,3-imidazolidin-2-one

1-(5-t-Butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one(8.0 grams), octanoyl chloride (5.5 grams) and pyridine (30 ml) werecharged into a glass reaction flash equipped with a mechanical stirrerand thermometer. The reaction mixture was stirred for several minutesand was then allowed to stand for a period of about 2 hours. After thistime water (100 ml) and hexane (30 ml) were added to the mixture. Theorganic phase was then separated from the aqueous phase and was washedwith water and dilute aqueous sodium bicarbonate. The washed solutionwas then dried over anhydrous magnesium sulfate and passed through a3-inch layer of Florex. The filtrate was then stripped of solvent,leaving a waxy solid residue. This residue was recrystallized frompentane to yield the desired product1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-octanoyloxy-1,3-imidazolidin-2-onehaving a melt point of 45° to 47° C.

For practical use as a herbicide the compound of this invention isgenerally incorporated into herbicidal compositions which comprise aninert carrier and a herbicidally toxic amount of the compound. Suchherbicidal compositions, which can also be called formulations, enablethe active compound to be applied conveniently to the site of the weedinfestation in any desired quantity. These compositions can be solidssuch as dusts, granules, or wettable powders; or they can be liquidssuch as solutions, aerosols, or emulsifiable concentrates.

For example, dusts can be prepared by grinding and blending the activecompound with a solid inert carrier such as the talcs, clays, silicas,pyrophyllite, and the like. Granular formulations can be prepared byimpregnating the compound, usually dissolved in a suitable solvent, ontoand into granulated carriers such as the attapulgites or thevermiculites, usually of a particle size range of from about 0.3 to 1.5mm. Wettable powders, which can be dispersed in water or oil to anydesired concentration of the active compound, can be prepared byincorporating wetting agents into concentrated dust compositions.

In some cases the active compound is sufficiently soluble in commonorganic solvents such as kerosene or xylene so that it can be useddirectly as a solution in these solvents. Frequently, solutions ofherbicides can be dispersed under superatmospheric pressure as aerosols.However, preferred liquid herbicidal compositions are emulsifiableconcentrates, which comprise the active compound according to thisinvention and as the inert carrier, a solvent and an emulsifier. Suchemulsifiable concentrates can be extended with water and/or oil to anydesired concentration of active compound for application as sprays tothe site of the weed infestation. The emulsifiers most commonly used inthese concentrates are nonionic or mixtures of nonionic with anionicsurface-active agents. With the use of some emulsifier systems aninverted emulsion (water in oil) can be prepared for direct applicationto weed infestations.

A typical herbicidal composition according to this invention isillustrated by the following example, in which the quantities are inparts by weight.

EXAMPLE 5 Preparation of a Dust

    ______________________________________                                        Product of Example 4  10                                                      Powdered Talc         90                                                      ______________________________________                                    

The above ingredients are mixed in a mechanical grinder-blender and areground until a homogeneous, free-flowing dust of the desired particlesize is obtained. This dust is suitable for direct application to thesite of the weed infestation.

The compound of this invention can be applied as a herbicide in anymanner recognized by the art. One method for the control of weedscomprises contacting the locus of said weeds with a herbicidalcomposition comprising an inert carrier and as an essential activeingredient, in a quantity which is herbicidally toxic to said weeds, thecompound of the present invention. The concentration of the new compoundof this invention in the herbicidal compositions will vary greatly withthe type of formulation and the purpose for which it is designed, butgenerally the herbicidal compositions will comprise from about 0.05 toabout 95 per cent by weight of the active compound of this invention. Ina preferred embodiment of this invention, the herbicidal compositionswill comprise from about 5 to about 75 per cent by weight of the activecompound. The compositions can also comprise such additional substancesas other pesticides, such as insecticides, nematocides, fungicides, andthe like; stabilizers, spreaders, deactivators, adhesives, stickers,fertilizers, activators, synergists, and the like.

The compound of the present invention is also useful when combined withother herbicides and/or defoliants, dessicants, growth inhibitors, andthe like in the herbicidal compositions heretofore described. Theseother materials can comprise from about 5% to about 95% of the activeingredients in the herbicidal compositions. Use of combinations of theseother herbicides and/or defoliants, dessicants, etc. with the compoundof the present invention provide herbicidal compositions which are moreeffective in controlling weeds and often provide results unattainablewith separate compositions of the individual herbicides. The otherherbicides, defoliants, dessicants and plant growth inhibitors, withwhich the compound of this invention can be used in the herbicidalcompositions to control weeds, can include chlorophenoxy herbicides suchas 2,4-D, 2,4,5-T, MCPA, MCPB, alachlor, 4(2,4-DB), 2,4-DEB, 4-CPB,4-CPA, 4-CPP, 2,4,5-TB, 2,4,5-TES, 3,4-DA, silvex and the like;carbamate herbicides such as IPC, CIPC, swep, barban, BCPC, CEPC, CPPCand the like; thiocarbamate and dithiocarbamate herbicides such as CDEC,metham sodium, EPTC, diallate, PEBC, perbulate, vernolate and the like;substituted urea herbicides such as norea, siduron, dichloral urea,chloroxuron, cycluron, fenuron, monuron, monuron TCA, diuron, linuron,monolinuron, neburon, buturon, trimeturon and the like; symmetricaltriazne herbicides such as simazine, chlorazine, atraone, desmetryne,norazne, ipazine, prometryn, atrazne, trietazine, simetone, prometone,propazine, ametryne, and the like; chloroacetamide herbicides such asalpha-chloro-N,N-dimethylacetamide, CDEA, CDAA,alpha-chloro-N-isopropylacetamide, 2-chloro-N-isopropylacetanilide,4-(chloroacetyl)-morpholine, 1-(chloroacetyl)piperidine, and the like;chlorinated aliphatic acid herbicides such as TCA, dalapon,2,3-dichloropropionic acid, 2,2,3-TPA and the like; chlorinated benzoicacid and phenylacetic acid herbicides such as 2,3,6-TBA, 2,3,5,6-TBA,dicamba, tricamba, amiben, fenac, PBA,2-methoxy-3,6-dichlorophenylacetic acid,3-methoxy-2,6-dichlorophenylacetic acid,2-methoxy-3,5,6-trichlorophenylacetic acid, 2,4-dichloro-3-nitrobenzoicacid the like; and such compounds as aminotriazole, maleic hydrazide,phenyl mercuric acetate, endothal, biuret, technical chlordane, dimethyl2,3,5,6-tetrachloroterephthalate, diquat, erbon, DNC, DNBP, dichlobenil,DPA, diphenamid, dipropalin, trifluralin, solan, dicryl, merphos, DMPA,DSMA, MSMA, potassium azide, acrolein, benefin, bensulide, AMS,bromacil,2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione,bromoxynil, cacodylic acid, CMA, CPMF, cypromid, DCB, DCPA, dichlone,diphenatril, DMTT, DNAP, EBEP, EXD, HCA, ioxynil, IPX, isocil, potassiumcyanate, MAA, MAMA, MCPES, MCPP, MH, molinate, NPA, OCH, paraquat, PCP,picloram, DPA, PCA, pyrichlor, sesone, terbacil, terbutol, TCBA,brominil, CP-50144, H-176-1, H-732, M-2901, planavin, sodiumtetraborate, calcium cyanamid, DEF, ethyl xanthogen disulfide, sindone,sindone B, propanil and the like. Such herbicides can also be used inthe methods and compositions of this invention in the form of theirsalts, esters, amides, and other derivatives whenever applicable to theparticular parent compounds.

Weeds are undesirable plants growing where they are not wanted, havingno economic value, and interfering with the production of cultivatedcrops, with the growing of ornamental plants, or with the welfare oflivestock. Many types of weeds are known, including annuals such aspigweed, lambsquarters, foxtails, crabgrass, wild mustard, fieldpennycress, ryegrass, goose grass, chickweed, wild oats, velvetleaf,purslane, barnyard grass, smartweed, knotweed, cocklebur, wildbuckwheat, kochia, medic, corn cockle, ragweed, sowthistle, coffeeweed,croton, cuphea, dodder, fumitory, groundsel, hemp nettle, knawel,spurge, spurry, emex, jungle rice, pondweed, dog fennel, carpetweed,morningglory, bedstraw, ducksalad, naiad, cheatgrass, fall panicum,jimsonweed, witchgrass, switchgrass, watergrass, teaweed, wild turnipand sprangletop; biennials such as wild carrot, matricaria, wild barley,campion, chamomile, burdock, mullein, roundleaved mallow, bull thistle,hounds-tongue, moth mullein and purple star thistle; or perennials suchas white cockle, perennial ryegrass, quackgrass, Johnson grass, Canadathistle, hedge bindweed, Bermuda grass, sheep sorrel, curly dock,nutgrass, field chickweed, dandelion, campanula, field bindweed, Russianknapweed, mesquite, toadflax, yarrow, aster, gromwell, horsetail,ironweed, sesbania, bulrush, cattail, wintercress, horsenettle,nutsedge, milkweed and sicklepod.

Similarly, such weeds can be classified as broadleaf or grassy weeds. Itis economically desirable to control the growth of such weeds withoutdamaging beneficial plants or livestock.

The new compound of this invention is particularly valuable for weedcontrol because it is toxic to many species and groups of weeds while itis relatively nontoxic to many beneficial plants. The exact amount ofthe compound required will depend on a variety of factors, including thehardiness of the particular weed species, weather, type of soil, methodof application, the kind of beneficial plants in the same area, and thelike. Thus, while the application of up to only about one or two ouncesof the active compound per acre may be sufficient for good control of alight infestation of weeds growing under adverse conditions, theapplication of ten pounds or more of active compound per acre may berequired for good control of a dense infestation of hardy perennialweeds growing under favorable conditions.

The herbicidal toxicity of the new compound of this invention can beillustrated by many of the established testing techniques known to theart, such as pre- and post-emergence testing.

The herbicidal activity of the compound of this invention wasdemonstrated by experiments carried out for the pre-emergency control ofa variety of weeds. In these experiments small plastic greenhouse potsfilled with dry soil were seeded with the various weed seeds.Twenty-four hours or less after seeding the pots were sprayed with wateruntil the soil was wet and the test compound formulated as an aqueousemulsion of an acetone solution containing emulsifiers was sprayed atthe indicated concentrations on the surface of the soil.

After spraying, the soil containers were placed in the greenhouse andprovided with supplementary heat as required and daily or more frequentwatering. The plants were maintained under these conditins for a periodof from 21 to 28 days, at which time the condition of the plants and thedegree of injury to the plants was rated on a scale of from 0 to 10, asfollows: 0 = no injury, 1,2 = slight injury, 3,4 = moderate injury, 5,6= moderately severe injury, 7,8,9 = severe injury and 10 = death. Theeffectiveness of the compound is demonstrated by the data in Table I.

                  TABLE I                                                         ______________________________________                                                           Injury Rating                                                        Days After                                                                             (Concentration in lbs/A)                                   Weed Species                                                                              Treatment  1/2      1/4    1/8                                    ______________________________________                                        Yellow Nutsedge                                                                           21         0        0      0                                                  28         0        0      0                                      Wild Oats   21         10       7      4                                                  28         10       10     10                                     Jimsonweed  21         5        0      2                                                  28         5        5      6                                      Velvetleaf  21         10       10     10                                                 28         10       10     10                                     Pigweed     21         9        0      5                                                  28         10       8      7                                      Wild Mustard                                                                              21         10       10     10                                                 28         10       10     10                                     Yellow Foxtail                                                                            21         7        4      3                                                  28         6        7      2                                      Barnyardgrass                                                                             21         9        3      8                                                  28         10       10     10                                     Crabgrass   21         3        2      0                                                  28         4        0      0                                      Cheatgrass  21         10       10     4                                                  28         10       10     9                                      Morningglory                                                                              21         10       7      6                                                  28         10       10     10                                     ______________________________________                                    

The herbicidal activity of the compound of this invention was alsodemonstrated by experiments carried out for the post-emergence controlof a variety of weeds. In these experiments the compounds was formulatedas an aqueous emulsion and sprayed at the indicated dosage on thefoliage of the weeds that have attained a prescribed size. Afterspraying, the plants were placed in a greenhouse and watered daily ormore frequently. Water was not applied to the foliage of the treatedplants. The severity of the injury was determined 14 days aftertreatment and was rated on the scale of from 0 to 10 heretoforedescribed. The effectiveness of the compound is demonstrated by the datain Table II.

                  TABLE II                                                        ______________________________________                                                     Injury Rating                                                                 (Concentration in lbs/A)                                         Weed Species   1/2       1/4       1/8                                        ______________________________________                                        Yellow Foxtail 10        10        10                                         Wild Mustard   10        10        10                                         Johnsongrass   10        10         4                                         Pigweed        10        10        10                                         Morningglory   10        10        10                                         Crabgrass      10        10         5                                         Wild Oats      10        10        10                                         Bindweed       10        10        10                                         Jimsonweed     10        10        10                                         Barnyardgrass  10        10        10                                         Yellow Nutsedge                                                                               4         3         2                                         ______________________________________                                    

I CLAIM:
 1. The compound1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-octanoyloxy-1,3-imidazolidin-2-one.2. A herbicidal composition comprising an inert carrier and, as anessential active ingredient, in a quantity toxic to weeds, the compoundof claim
 1. 3. A method of controlling weeds which comprises contactingthe weeds with a herbicidal composition comprising an inert carrier and,as an essential active ingredient, in a quantity toxic to weeds, thecompound of claim 1.